Humans acquire their most important single ally from the animal kingdom when they domesticate the horse, in about 3000 BC.

Wild horses of various kinds have spread throughout most of the world by the time human history begins. Their bones feature among the remains of early human meals, and they appear in cave paintings with other animals of the chase. Some of their earliest fossil remains have been found in America, but after arriving across the Bering Land Bridge they become extinct in that continent. They are reintroduced by European colonists in the 16th century.

A natural habitat of the wild horse is the steppes of central Asia. Here, with its ability to move fast and far, it can gallop out of harm's way and make the most of scarce grazing. And here, some 5000 years ago, humans first capture, tame and breed the horse. The original purpose, as with cattle, is to acquire a reliable source of meat and subsequently milk. But then, in a crucial development, tribesmen discover that they have at their disposal a means of transport.

With a horse beneath him, man's ability to move is improved out of all recognition. The next comparable moment in the story of human speed does not arrive for another 5000 years - with steam trains.

The first domesticated horses are of a size which we would describe as ponies. Horses of this kind were still living in the wild in Mongolia until quite recent times. Discovered there in the 1870s, and named Przewalski's horse, they survive now only in zoos.

The entire range of horses known to us, from the mighty carthorse down to the smallest ponies, is the result of human breeding. Other wild breeds, now extinct, have been added to the stock. One such example is the tarpan, which was the native breed in Europe.

Asses: 3000 BC

At much the same time as the wild horse is being domesticated in the region of the Black Sea and the Caspian, its cousin the ass or donkey (a member of the same equus family) is tamed in Egypt. At this time the donkey appears to have roamed wild in northeast Africa and up through the Fertile Crescent into Mesopotamia.

So both horse and the ass, from north and from south, become available to two of the earliest civilizations - in Mesopotamia and Egypt.

Silk moths: 3000 BC

In China an indigenous silk moth is co-opted for man's purposes. Bombyx mori is still the only insect to have been fully domesticated (in the sense that, unlike the bee, it cannot live in the wild and is not known in a wild form). The silk moth has lost the power to fly; its caterpillar can find no mulberry leaves for itself. The species exists, and survives, only because humans like silk.

The earliest known silk from bombyx mori was found in a bamboo basket unearthed by archaeologists in China. Other pieces in the same basket were from wild silkworms. The fragments date from between 2850 and 2650 BC.

Camels: 3000-1500 BC

As beasts of burden and transport, camels occupy an important place alongside horses and donkeys. Two small members of the camel family, the llama and the alpaca of south America, are domesticated first - probably before 3000 BC. At that time both species appear to have been on the verge of extinction. Domestication by the American Indians saves them. Neither the llama nor the alpaca exists now in the wild.

The larger of the two, the llama, is primarily a beast of burden, while the shaggy alpaca is valuable for its wool. Neither animal is strong enough to pull a plough or drag a cart - two important steps in the story of civilization which are denied to the early Americans.

In the parched regions of north Africa and Asia two different species of camel become the most important beasts of burden - the single-humped Arabian camel (in north Africa, the Middle East, India) and the double-humped Bactrian camel (central Asia, Mongolia). Both are well adapted to desert conditions. They can derive water, when none is available elsewhere, from the fat stored in their humps.

It is probable that they are first domesticated in Arabia some time after 1500 BC. By about 1000 BC caravans of camels are bringing precious goods up the west coast of Arabia, linking India with the Mediterranean and Mesopotamia.

Poultry and pigeons: 2000 BC

The red jungle fowl, a member of the pheasant family, lives in the forests and bamboo jungles of India and southeast Asia. The male makes an impressive crowing sound and is dignified by a comb on his head and wattles under his beak. Jungle fowl of this kind are captured and kept for their eggs and their flesh by about 2000 BC in Asia. It is thought that all domestic poultry in the world today are descended from this one species.

At much the same period, in Egypt, pigeons are first persuaded to live and breed in the proximity of humans - again as a reliable source of protein. But some 3000 years later it is discovered that they have an extra and unusual talent. Some of them can be trained to fly home.

Elephants: 2000 BC

India is the region where elephants are first tamed, during the Indus civilization. The two species of elephant are at this time widespread - the Indian elephant throughout temperate Asia as far west as Syria, and the African elephant in regions north and south of the Sahara. (The mammoth has become extinct by the end of the last glacial period, about 10,000 years ago - partly through climatic changes and partly at the hands of human hunters.)

It is not known when elephants are first trained to take part in war, but by the 3rd century BC they are a valuable military force in both India and north Africa. An ability to learn tricks also makes the elephant a performing animal, popular in the arena of the Roman circus.

The honey of the bee: before the 6th century BC

No doubt hunter-gatherers, when they find the honey of bees in a hollow tree, often risk a sting for the pleasure of sweetness. The story of beekeeping can be described as the search for safer and more convenient ways of robbing a bees' nest.

The turning point in the domestication of the bee is the discovery that a swarm of bees can be coaxed into a specific nest - one designed by man for his own convenience in collecting the honey, and with it the useful substance of beeswax.

It is not known when the beehive is first developed, but the Greeks in classical times use a design which for centuries remains standard in much of Europe. Known as a skep, it is a dome constructed from a continuous coil of woven straw - looking much like an upturned basket. It stands on a wooden platform with a hole in, through which the bees enter.

The disadvantage of such a system is that the removal of the honey involves disturbing the nest of the bees. From the 17th century, when wooden hives come into use, extra chambers are added for the collection of honey. But the major improvement in beekeeping techniques is the achievement of a 19th-century clergyman, L.L. Langstroth.

Rabbits: from the 1st century BC

Since Roman times, if not before, people have encouraged rabbits to breed in captivity for the sake of their meat, and have then regretted doing so because of the animal's ability to burrow to freedom and eat the crops. The only safe place to keep rabbits is on an island. (Almost every island of the world has rabbits on, brought by humans to establish a living larder for passing ships.)

Rabbits are inaccessible in their burrows, so man domesticates a species of polecat (in the form of the ferret) to flush them out. As early as the 1st century AD Pliny describes the use of ferrets in the Balearic islands, as the inhabitants struggle to control the rabbits (see Pliny and the ferrets).